Shader: Move attribute parsing to parser, simplifying writer code

include/Nazara/Shader/Ast/ExpressionType.hpp

@@ -11,6 +11,7 @@
 #include <Nazara/Utility/Enums.hpp>
 #include <Nazara/Shader/ShaderEnums.hpp>
 #include <Nazara/Shader/Ast/Attribute.hpp>
+#include <optional>
 #include <string>
 #include <variant>
 #include <vector>
@@ -81,11 +82,13 @@ namespace Nz::ShaderAst
 	{
 		struct StructMember
 		{
+			std::optional<BuiltinEntry> builtin;
+			std::optional<unsigned int> locationIndex;
 			std::string name;
-			std::vector<Attribute> attributes;
 			ExpressionType type;
 		};
 
+		std::optional<StructLayout> layout;
 		std::string name;
 		std::vector<StructMember> members;
 	};

include/Nazara/Shader/GlslWriter.hpp

@@ -71,7 +71,7 @@ namespace Nz
 			void HandleEntryPoint(ShaderAst::DeclareFunctionStatement& node);
 			void HandleInOut();
 
-			void RegisterStruct(std::size_t structIndex, bool isStd140, ShaderAst::StructDescription desc);
+			void RegisterStruct(std::size_t structIndex, ShaderAst::StructDescription desc);
 			void RegisterVariable(std::size_t varIndex, std::string varName);
 
 			void Visit(ShaderAst::ExpressionPtr& expr, bool encloseIfRequired = false);

include/Nazara/Shader/ShaderAstSerializer.hpp

@@ -48,7 +48,6 @@ namespace Nz::ShaderAst
 			void Serialize(ReturnStatement& node);
 
 		protected:
-			void Attributes(std::vector<Attribute>& attributes);
 			template<typename T> void Container(T& container);
 			template<typename T> void Enum(T& enumVal);
 			template<typename T> void OptEnum(std::optional<T>& optVal);

include/Nazara/Shader/ShaderBuilder.hpp

@@ -10,6 +10,7 @@
 #include <Nazara/Prerequisites.hpp>
 #include <Nazara/Shader/ShaderNodes.hpp>
 #include <memory>
+#include <optional>
 
 namespace Nz::ShaderBuilder
 {
@@ -59,13 +60,12 @@ namespace Nz::ShaderBuilder
 		struct DeclareFunction
 		{
 			inline std::unique_ptr<ShaderAst::DeclareFunctionStatement> operator()(std::string name, std::vector<ShaderAst::DeclareFunctionStatement::Parameter> parameters, std::vector<ShaderAst::StatementPtr> statements, ShaderAst::ExpressionType returnType = ShaderAst::NoType{}) const;
-			inline std::unique_ptr<ShaderAst::DeclareFunctionStatement> operator()(std::vector<ShaderAst::Attribute> attributes, std::string name, std::vector<ShaderAst::DeclareFunctionStatement::Parameter> parameters, std::vector<ShaderAst::StatementPtr> statements, ShaderAst::ExpressionType returnType = ShaderAst::NoType{}) const;
+			inline std::unique_ptr<ShaderAst::DeclareFunctionStatement> operator()(std::optional<ShaderStageType> entryStage, std::string name, std::vector<ShaderAst::DeclareFunctionStatement::Parameter> parameters, std::vector<ShaderAst::StatementPtr> statements, ShaderAst::ExpressionType returnType = ShaderAst::NoType{}) const;
 		};
 
 		struct DeclareStruct
 		{
 			inline std::unique_ptr<ShaderAst::DeclareStructStatement> operator()(ShaderAst::StructDescription description) const;
-			inline std::unique_ptr<ShaderAst::DeclareStructStatement> operator()(std::vector<ShaderAst::Attribute> attributes, ShaderAst::StructDescription description) const;
 		};
 
 		struct DeclareVariable

include/Nazara/Shader/ShaderBuilder.inl

@@ -108,10 +108,10 @@ namespace Nz::ShaderBuilder
 		return declareFunctionNode;
 	}
 
-	inline std::unique_ptr<ShaderAst::DeclareFunctionStatement> Impl::DeclareFunction::operator()(std::vector<ShaderAst::Attribute> attributes, std::string name, std::vector<ShaderAst::DeclareFunctionStatement::Parameter> parameters, std::vector<ShaderAst::StatementPtr> statements, ShaderAst::ExpressionType returnType) const
+	inline std::unique_ptr<ShaderAst::DeclareFunctionStatement> Impl::DeclareFunction::operator()(std::optional<ShaderStageType> entryStage, std::string name, std::vector<ShaderAst::DeclareFunctionStatement::Parameter> parameters, std::vector<ShaderAst::StatementPtr> statements, ShaderAst::ExpressionType returnType) const
 	{
 		auto declareFunctionNode = std::make_unique<ShaderAst::DeclareFunctionStatement>();
-		declareFunctionNode->attributes = std::move(attributes);
+		declareFunctionNode->entryStage = entryStage;
 		declareFunctionNode->name = std::move(name);
 		declareFunctionNode->parameters = std::move(parameters);
 		declareFunctionNode->returnType = std::move(returnType);
@@ -128,15 +128,6 @@ namespace Nz::ShaderBuilder
 		return declareStructNode;
 	}
 
-	inline std::unique_ptr<ShaderAst::DeclareStructStatement> Impl::DeclareStruct::operator()(std::vector<ShaderAst::Attribute> attributes, ShaderAst::StructDescription description) const
-	{
-		auto declareStructNode = std::make_unique<ShaderAst::DeclareStructStatement>();
-		declareStructNode->attributes = std::move(attributes);
-		declareStructNode->description = std::move(description);
-
-		return declareStructNode;
-	}
-
 	inline std::unique_ptr<ShaderAst::DeclareVariableStatement> Nz::ShaderBuilder::Impl::DeclareVariable::operator()(std::string name, ShaderAst::ExpressionType type, ShaderAst::ExpressionPtr initialValue) const
 	{
 		auto declareVariableNode = std::make_unique<ShaderAst::DeclareVariableStatement>();

include/Nazara/Shader/ShaderEnums.hpp

@@ -25,14 +25,6 @@ namespace Nz::ShaderAst
 		Location   //< Location (struct member only) - has argument index
 	};
 
-	enum class PrimitiveType
-	{
-		Boolean, //< bool
-		Float32, //< f32
-		Int32,   //< i32
-		UInt32,  //< ui32
-	};
-
 	enum class BinaryType
 	{
 		Add,       //< +
@@ -80,6 +72,14 @@ namespace Nz::ShaderAst
 #include <Nazara/Shader/ShaderAstNodes.hpp>
 	};
 
+	enum class PrimitiveType
+	{
+		Boolean, //< bool
+		Float32, //< f32
+		Int32,   //< i32
+		UInt32,  //< ui32
+	};
+
 	enum class SwizzleComponent
 	{
 		First,

include/Nazara/Shader/ShaderLangParser.hpp

@@ -14,6 +14,12 @@
 
 namespace Nz::ShaderLang
 {
+	class AttributeError : public std::exception
+	{
+		public:
+			using exception::exception;
+	};
+	
 	class ExpectedToken : public std::exception
 	{
 		public:

include/Nazara/Shader/ShaderNodes.hpp

@@ -210,13 +210,12 @@ namespace Nz::ShaderAst
 
 		struct ExternalVar
 		{
+			std::optional<unsigned int> bindingIndex;
 			std::string name;
-			std::vector<Attribute> attributes;
 			ExpressionType type;
 		};
 
 		std::optional<std::size_t> varIndex;
-		std::vector<Attribute> attributes;
 		std::vector<ExternalVar> externalVars;
 	};
 
@@ -231,10 +230,10 @@ namespace Nz::ShaderAst
 			ExpressionType type;
 		};
 
+		std::optional<ShaderStageType> entryStage;
 		std::optional<std::size_t> funcIndex;
 		std::optional<std::size_t> varIndex;
 		std::string name;
-		std::vector<Attribute> attributes;
 		std::vector<Parameter> parameters;
 		std::vector<StatementPtr> statements;
 		ExpressionType returnType;
@@ -246,7 +245,6 @@ namespace Nz::ShaderAst
 		void Visit(AstStatementVisitor& visitor) override;
 
 		std::optional<std::size_t> structIndex;
-		std::vector<Attribute> attributes;
 		StructDescription description;
 	};
 

src/Nazara/Shader/GlslWriter.cpp

@@ -24,12 +24,6 @@ namespace Nz
 		static const char* s_outputPrefix = "_NzOut_";
 		static const char* s_outputVarName = "_nzOutput";
 
-		//FIXME: Have this only once
-		std::unordered_map<std::string, ShaderStageType> s_entryPoints = {
-			{ "frag", ShaderStageType::Fragment },
-			{ "vert", ShaderStageType::Vertex },
-		};
-
 		template<typename T> const T& Retrieve(const std::unordered_map<std::size_t, T>& map, std::size_t id)
 		{
 			auto it = map.find(id);
@@ -49,29 +43,19 @@ namespace Nz
 				ShaderAst::DeclareFunctionStatement* func = static_cast<ShaderAst::DeclareFunctionStatement*>(clone.get());
 
 				// Remove function if it's an entry point of another type than the one selected
-				bool isEntryPoint = false;
+				if (node.entryStage)
-				for (auto& attribute : func->attributes)
 				{
-					if (attribute.type == ShaderAst::AttributeType::Entry)
+					ShaderStageType stage = *node.entryStage;
-					{
+					if (stage != selectedStage)
-						auto it = s_entryPoints.find(std::get<std::string>(attribute.args));
-						assert(it != s_entryPoints.end());
-
-						if (it->second != selectedEntryPoint)
 						return ShaderBuilder::NoOp();
 
-						isEntryPoint = true;
-						break;
-					}
-				}
-
-				if (isEntryPoint)
 					entryPoint = func;
+				}
 
 				return clone;
 			}
 
-			ShaderStageType selectedEntryPoint;
+			ShaderStageType selectedStage;
 			ShaderAst::DeclareFunctionStatement* entryPoint = nullptr;
 		};
 
@@ -81,8 +65,8 @@ namespace Nz
 			ShaderStageTypeFlags stageFlags;
 		};
 
-		std::unordered_map<std::string, Builtin> builtinMapping = {
+		std::unordered_map<ShaderAst::BuiltinEntry, Builtin> s_builtinMapping = {
-			{ "position", { "gl_Position", ShaderStageType::Vertex } }
+			{ ShaderAst::BuiltinEntry::VertexPosition, { "gl_Position", ShaderStageType::Vertex } }
 		};
 	}
 
@@ -95,17 +79,11 @@ namespace Nz
 			std::string targetName;
 		};
 
-		struct StructInfo
-		{
-			ShaderAst::StructDescription structDesc;
-			bool isStd140 = false;
-		};
-
 		ShaderStageType stage;
 		const States* states = nullptr;
 		ShaderAst::DeclareFunctionStatement* entryFunc = nullptr;
 		std::stringstream stream;
-		std::unordered_map<std::size_t, StructInfo> structs;
+		std::unordered_map<std::size_t, ShaderAst::StructDescription> structs;
 		std::unordered_map<std::size_t, std::string> variableNames;
 		std::vector<InOutField> inputFields;
 		std::vector<InOutField> outputFields;
@@ -138,7 +116,7 @@ namespace Nz
 		ShaderAst::StatementPtr transformedShader = transformVisitor.Transform(shader);
 
 		PreVisitor previsitor;
-		previsitor.selectedEntryPoint = shaderStage;
+		previsitor.selectedStage = shaderStage;
 
 		ShaderAst::StatementPtr adaptedShader = previsitor.Clone(transformedShader);
 
@@ -241,13 +219,13 @@ namespace Nz
 
 	void GlslWriter::Append(const ShaderAst::StructType& structType)
 	{
-		const auto& structDesc = Retrieve(m_currentState->structs, structType.structIndex).structDesc;
+		const auto& structDesc = Retrieve(m_currentState->structs, structType.structIndex);
 		Append(structDesc.name);
 	}
 
 	void GlslWriter::Append(const ShaderAst::UniformType& uniformType)
 	{
-		/* TODO */
+		throw std::runtime_error("unexpected UniformType");
 	}
 
 	void GlslWriter::Append(const ShaderAst::VectorType& vecType)
@@ -305,7 +283,7 @@ namespace Nz
 
 	void GlslWriter::AppendField(std::size_t structIndex, const std::size_t* memberIndices, std::size_t remainingMembers)
 	{
-		const auto& structDesc = Retrieve(m_currentState->structs, structIndex).structDesc;
+		const auto& structDesc = Retrieve(m_currentState->structs, structIndex);
 
 		const auto& member = structDesc.members[*memberIndices];
 
@@ -371,7 +349,7 @@ namespace Nz
 
 				assert(IsStructType(parameter.type));
 				std::size_t structIndex = std::get<ShaderAst::StructType>(parameter.type).structIndex;
-				const ShaderAst::StructDescription& structDesc = Retrieve(m_currentState->structs, structIndex).structDesc;
+				const ShaderAst::StructDescription& structDesc = Retrieve(m_currentState->structs, structIndex);
 
 				AppendLine(structDesc.name, " ", varName, ";");
 				for (const auto& [memberName, targetName] : m_currentState->inputFields)
@@ -397,41 +375,24 @@ namespace Nz
 		{
 			for (const auto& member : structDesc.members)
 			{
-				bool skip = false;
+				if (member.builtin)
-				std::optional<std::string> builtinName;
-				std::optional<long long> attributeLocation;
-				for (const auto& [attributeType, attributeParam] : member.attributes)
-				{
-					if (attributeType == ShaderAst::AttributeType::Builtin)
-					{
-						auto it = builtinMapping.find(std::get<std::string>(attributeParam));
-						if (it != builtinMapping.end())
 				{
+					auto it = s_builtinMapping.find(member.builtin.value());
+					assert(it != s_builtinMapping.end());
+
 					const Builtin& builtin = it->second;
 					if (!builtin.stageFlags.Test(m_currentState->stage))
-							{
+						continue; //< This builtin is not active in this stage, skip it
-								skip = true;
-								break;
-							}
 
-							builtinName = builtin.identifier;
+					fields.push_back({
-							break;
+						member.name,
+						builtin.identifier
+					});
 				}
-					}
+				else if (member.locationIndex)
-					else if (attributeType == ShaderAst::AttributeType::Location)
-					{
-						attributeLocation = std::get<long long>(attributeParam);
-						break;
-					}
-				}
-
-				if (skip)
-					continue;
-
-				if (attributeLocation)
 				{
 					Append("layout(location = ");
-					Append(*attributeLocation);
+					Append(*member.locationIndex);
 					Append(") ");
 					Append(keyword);
 					Append(" ");
@@ -446,13 +407,6 @@ namespace Nz
 						targetPrefix + member.name
 					});
 				}
-				else if (builtinName)
-				{
-					fields.push_back({
-						member.name,
-						*builtinName
-					});
-				}
 			}
 			AppendLine();
 		};
@@ -468,7 +422,7 @@ namespace Nz
 			assert(std::holds_alternative<ShaderAst::StructType>(parameter.type));
 
 			std::size_t inputStructIndex = std::get<ShaderAst::StructType>(parameter.type).structIndex;
-			inputStruct = &Retrieve(m_currentState->structs, inputStructIndex).structDesc;
+			inputStruct = &Retrieve(m_currentState->structs, inputStructIndex);
 
 			AppendCommentSection("Inputs");
 			AppendInOut(*inputStruct, m_currentState->inputFields, "in", s_inputPrefix);
@@ -485,20 +439,17 @@ namespace Nz
 			assert(std::holds_alternative<ShaderAst::StructType>(node.returnType));
 			std::size_t outputStructIndex = std::get<ShaderAst::StructType>(node.returnType).structIndex;
 
-			const ShaderAst::StructDescription& outputStruct = Retrieve(m_currentState->structs, outputStructIndex).structDesc;
+			const ShaderAst::StructDescription& outputStruct = Retrieve(m_currentState->structs, outputStructIndex);
 
 			AppendCommentSection("Outputs");
 			AppendInOut(outputStruct, m_currentState->outputFields, "out", s_outputPrefix);
 		}
 	}
 
-	void GlslWriter::RegisterStruct(std::size_t structIndex, bool isStd140, ShaderAst::StructDescription desc)
+	void GlslWriter::RegisterStruct(std::size_t structIndex, ShaderAst::StructDescription desc)
 	{
 		assert(m_currentState->structs.find(structIndex) == m_currentState->structs.end());
-		m_currentState->structs.emplace(structIndex, State::StructInfo{
+		m_currentState->structs.emplace(structIndex, std::move(desc));
-			std::move(desc),
-			isStd140
-		});
 	}
 
 	void GlslWriter::RegisterVariable(std::size_t varIndex, std::string varName)
@@ -667,16 +618,6 @@ namespace Nz
 
 		for (const auto& externalVar : node.externalVars)
 		{
-			std::optional<long long> bindingIndex;
-			for (const auto& [attributeType, attributeParam] : externalVar.attributes)
-			{
-				if (attributeType == ShaderAst::AttributeType::Binding)
-				{
-					bindingIndex = std::get<long long>(attributeParam);
-					break;
-				}
-			}
-
 			bool isStd140 = false;
 			if (IsUniformType(externalVar.type))
 			{
@@ -685,13 +626,13 @@ namespace Nz
 
 				std::size_t structIndex = std::get<ShaderAst::StructType>(uniform.containedType).structIndex;
 				auto& structInfo = Retrieve(m_currentState->structs, structIndex);
-				isStd140 = structInfo.isStd140;
+				isStd140 = structInfo.layout == StructLayout_Std140;
 			}
 
-			if (bindingIndex)
+			if (externalVar.bindingIndex)
 			{
 				Append("layout(binding = ");
-				Append(*bindingIndex);
+				Append(*externalVar.bindingIndex);
 				if (isStd140)
 					Append(", std140");
 
@@ -708,19 +649,19 @@ namespace Nz
 						assert(std::holds_alternative<ShaderAst::StructType>(uniform.containedType));
 
 						std::size_t structIndex = std::get<ShaderAst::StructType>(uniform.containedType).structIndex;
-						auto& structInfo = Retrieve(m_currentState->structs, structIndex);
+						auto& structDesc = Retrieve(m_currentState->structs, structIndex);
 
 						bool first = true;
-						for (const auto& [name, attribute, type] : structInfo.structDesc.members)
+						for (const auto& member : structDesc.members)
 						{
 							if (!first)
 								AppendLine();
 
 							first = false;
 
-							Append(type);
+							Append(member.type);
 							Append(" ");
-							Append(name);
+							Append(member.name);
 							Append(";");
 						}
 					}
@@ -778,34 +719,24 @@ namespace Nz
 
 	void GlslWriter::Visit(ShaderAst::DeclareStructStatement& node)
 	{
-		bool isStd140 = false;
-		for (const auto& [attributeType, attributeParam] : node.attributes)
-		{
-			if (attributeType == ShaderAst::AttributeType::Layout && std::get<std::string>(attributeParam) == "std140")
-			{
-				isStd140 = true;
-				break;
-			}
-		}
-
 		assert(node.structIndex);
-		RegisterStruct(*node.structIndex, isStd140, node.description);
+		RegisterStruct(*node.structIndex, node.description);
 
 		Append("struct ");
 		AppendLine(node.description.name);
 		EnterScope();
 		{
 			bool first = true;
-			for (const auto& [name, attribute, type] : node.description.members)
+			for (const auto& member : node.description.members)
 			{
 				if (!first)
 					AppendLine();
 
 				first = false;
 
-				Append(type);
+				Append(member.type);
 				Append(" ");
-				Append(name);
+				Append(member.name);
 				Append(";");
 			}
 		}
@@ -897,7 +828,7 @@ namespace Nz
 			const ShaderAst::ExpressionType& returnType = GetExpressionType(*node.returnExpr);
 			assert(IsStructType(returnType));
 			std::size_t structIndex = std::get<ShaderAst::StructType>(returnType).structIndex;
-			const ShaderAst::StructDescription& structDesc = Retrieve(m_currentState->structs, structIndex).structDesc;
+			const ShaderAst::StructDescription& structDesc = Retrieve(m_currentState->structs, structIndex);
 
 			std::string outputStructVarName;
 			if (node.returnExpr->GetType() == ShaderAst::NodeType::VariableExpression)

src/Nazara/Shader/ShaderAstCloner.cpp

@@ -45,7 +45,6 @@ namespace Nz::ShaderAst
 	StatementPtr AstCloner::Clone(DeclareExternalStatement& node)
 	{
 		auto clone = std::make_unique<DeclareExternalStatement>();
-		clone->attributes = node.attributes;
 		clone->externalVars = node.externalVars;
 		clone->varIndex = node.varIndex;
 
@@ -55,7 +54,7 @@ namespace Nz::ShaderAst
 	StatementPtr AstCloner::Clone(DeclareFunctionStatement& node)
 	{
 		auto clone = std::make_unique<DeclareFunctionStatement>();
-		clone->attributes = node.attributes;
+		clone->entryStage = node.entryStage;
 		clone->funcIndex = node.funcIndex;
 		clone->name = node.name;
 		clone->parameters = node.parameters;

src/Nazara/Shader/ShaderAstSerializer.cpp

@@ -115,6 +115,7 @@ namespace Nz::ShaderAst
 
 	void AstSerializerBase::Serialize(DeclareVariableStatement& node)
 	{
+		OptVal(node.varIndex);
 		Value(node.varName);
 		Type(node.varType);
 		Node(node.initialExpression);
@@ -168,14 +169,14 @@ namespace Nz::ShaderAst
 
 	void AstSerializerBase::Serialize(DeclareExternalStatement& node)
 	{
-		Attributes(node.attributes);
+		OptVal(node.varIndex);
 
 		Container(node.externalVars);
 		for (auto& extVar : node.externalVars)
 		{
-			Attributes(extVar.attributes);
 			Value(extVar.name);
 			Type(extVar.type);
+			OptVal(extVar.bindingIndex);
 		}
 	}
 
@@ -183,8 +184,9 @@ namespace Nz::ShaderAst
 	{
 		Value(node.name);
 		Type(node.returnType);
-
+		OptEnum(node.entryStage);
-		Attributes(node.attributes);
+		OptVal(node.funcIndex);
+		OptVal(node.varIndex);
 
 		Container(node.parameters);
 		for (auto& parameter : node.parameters)
@@ -200,13 +202,18 @@ namespace Nz::ShaderAst
 
 	void AstSerializerBase::Serialize(DeclareStructStatement& node)
 	{
+		OptVal(node.structIndex);
+
 		Value(node.description.name);
+		OptEnum(node.description.layout);
 
 		Container(node.description.members);
 		for (auto& member : node.description.members)
 		{
 			Value(member.name);
 			Type(member.type);
+			OptEnum(member.builtin);
+			OptVal(member.locationIndex);
 		}
 	}
 
@@ -246,78 +253,6 @@ namespace Nz::ShaderAst
 		m_stream.FlushBits();
 	}
 	
-	void AstSerializerBase::Attributes(std::vector<Attribute>& attributes)
-	{
-		Container(attributes);
-		for (auto& attribute : attributes)
-		{
-			Enum(attribute.type);
-
-			if (IsWriting())
-			{
-				std::visit([&](auto&& arg)
-				{
-					using T = std::decay_t<decltype(arg)>;
-
-					if constexpr (std::is_same_v<T, std::monostate>)
-					{
-						UInt8 typeId = 0;
-						Value(typeId);
-					}
-					else if constexpr (std::is_same_v<T, long long>)
-					{
-						UInt8 typeId = 1;
-						UInt64 v = UInt64(arg);
-						Value(typeId);
-						Value(v);
-					}
-					else if constexpr (std::is_same_v<T, std::string>)
-					{
-						UInt8 typeId = 2;
-						Value(typeId);
-						Value(arg);
-					}
-					else
-						static_assert(AlwaysFalse<T>::value, "non-exhaustive visitor");
-
-				}, attribute.args);
-			}
-			else
-			{
-				UInt8 typeId;
-				Value(typeId);
-
-				switch (typeId)
-				{
-					case 0:
-						attribute.args.emplace<std::monostate>();
-						break;
-
-					case 1:
-					{
-						UInt64 arg;
-						Value(arg);
-
-						attribute.args = static_cast<long long>(arg);
-						break;
-					}
-
-					case 2:
-					{
-						std::string arg;
-						Value(arg);
-
-						attribute.args = std::move(arg);
-						break;
-					}
-
-					default:
-						throw std::runtime_error("invalid attribute type id");
-				}
-			}
-		}
-	}
-
 	bool ShaderAstSerializer::IsWriting() const
 	{
 		return true;

src/Nazara/Shader/ShaderAstValidator.cpp

@@ -11,14 +11,6 @@
 
 namespace Nz::ShaderAst
 {
-	namespace
-	{
-		std::unordered_map<std::string, ShaderStageType> entryPoints = {
-			{ "frag", ShaderStageType::Fragment },
-			{ "vert", ShaderStageType::Vertex },
-		};
-	}
-
 	struct AstError
 	{
 		std::string errMsg;
@@ -28,7 +20,7 @@ namespace Nz::ShaderAst
 	{
 		std::array<DeclareFunctionStatement*, ShaderStageTypeCount> entryFunctions = {};
 		std::unordered_set<std::string> declaredExternalVar;
-		std::unordered_set<long long> usedBindingIndexes;
+		std::unordered_set<unsigned int> usedBindingIndexes;
 	};
 
 	bool AstValidator::Validate(StatementPtr& node, std::string* error)
@@ -552,44 +544,15 @@ namespace Nz::ShaderAst
 
 	void AstValidator::Visit(DeclareExternalStatement& node)
 	{
-		if (!node.attributes.empty())
-			throw AstError{ "unhandled attribute for external block" };
-
-		/*for (const auto& [attributeType, arg] : node.attributes)
-		{
-			switch (attributeType)
-			{
-				default:
-					throw AstError{ "unhandled attribute for external block" };
-			}
-		}*/
-
 		for (const auto& extVar : node.externalVars)
 		{
-			bool hasBinding = false;
+			if (extVar.bindingIndex)
-			for (const auto& [attributeType, arg] : extVar.attributes)
 			{
-				switch (attributeType)
+				unsigned int bindingIndex = extVar.bindingIndex.value();
-				{
-					case AttributeType::Binding:
-					{
-						if (hasBinding)
-							throw AstError{ "attribute binding must be present once" };
-
-						if (!std::holds_alternative<long long>(arg))
-							throw AstError{ "attribute binding requires a string parameter" };
-
-						long long bindingIndex = std::get<long long>(arg);
 				if (m_context->usedBindingIndexes.find(bindingIndex) != m_context->usedBindingIndexes.end())
 					throw AstError{ "Binding #" + std::to_string(bindingIndex) + " is already in use" };
 
 				m_context->usedBindingIndexes.insert(bindingIndex);
-						break;
-					}
-
-					default:
-						throw AstError{ "unhandled attribute for external variable" };
-				}
 			}
 
 			if (m_context->declaredExternalVar.find(extVar.name) != m_context->declaredExternalVar.end())
@@ -603,42 +566,17 @@ namespace Nz::ShaderAst
 
 	void AstValidator::Visit(DeclareFunctionStatement& node)
 	{
-		bool hasEntry = false;
+		if (node.entryStage)
-		for (const auto& [attributeType, arg] : node.attributes)
 		{
-			switch (attributeType)
+			ShaderStageType stageType = *node.entryStage;
-			{
-				case AttributeType::Entry:
-				{
-					if (hasEntry)
-						throw AstError{ "attribute entry must be present once" };
-
-					if (!std::holds_alternative<std::string>(arg))
-						throw AstError{ "attribute entry requires a string parameter" };
-
-					const std::string& argStr = std::get<std::string>(arg);
-
-					auto it = entryPoints.find(argStr);
-					if (it == entryPoints.end())
-						throw AstError{ "invalid parameter " + argStr + " for entry attribute" };
-
-					ShaderStageType stageType = it->second;
 
 			if (m_context->entryFunctions[UnderlyingCast(stageType)])
 				throw AstError{ "the same entry type has been defined multiple times" };
 
-					m_context->entryFunctions[UnderlyingCast(it->second)] = &node;
+			m_context->entryFunctions[UnderlyingCast(stageType)] = &node;
 
 			if (node.parameters.size() > 1)
 				throw AstError{ "entry functions can either take one struct parameter or no parameter" };
-
-					hasEntry = true;
-					break;
-				}
-
-				default:
-					throw AstError{ "unhandled attribute for function" };
-			}
 		}
 
 		for (auto& statement : node.statements)

src/Nazara/Shader/ShaderLangParser.cpp

@@ -30,6 +30,24 @@ namespace Nz::ShaderLang
 			{ "layout",   ShaderAst::AttributeType::Layout   },
 			{ "location", ShaderAst::AttributeType::Location },
 		};
+
+		std::unordered_map<std::string, ShaderStageType> s_entryPoints = {
+			{ "frag", ShaderStageType::Fragment },
+			{ "vert", ShaderStageType::Vertex },
+		};
+
+		std::unordered_map<std::string, ShaderAst::BuiltinEntry> s_builtinMapping = {
+			{ "position", ShaderAst::BuiltinEntry::VertexPosition }
+		};
+
+		template<typename T, typename U>
+		std::optional<T> BoundCast(U val)
+		{
+			if (val < std::numeric_limits<T>::min() || val > std::numeric_limits<T>::max())
+				return std::nullopt;
+
+			return static_cast<T>(val);
+		}
 	}
 
 	ShaderAst::StatementPtr Parser::Parse(const std::vector<Token>& tokens)
@@ -305,14 +323,15 @@ namespace Nz::ShaderLang
 
 	ShaderAst::StatementPtr Parser::ParseExternalBlock(std::vector<ShaderAst::Attribute> attributes)
 	{
+		if (!attributes.empty())
+			throw AttributeError{ "unhandled attribute for external block" };
+
 		Expect(Advance(), TokenType::External);
 		Expect(Advance(), TokenType::OpenCurlyBracket);
 
 		std::unique_ptr<ShaderAst::DeclareExternalStatement> externalStatement = std::make_unique<ShaderAst::DeclareExternalStatement>();
-		externalStatement->attributes = std::move(attributes);
 
 		bool first = true;
-
 		for (;;)
 		{
 			if (!first)
@@ -336,7 +355,32 @@ namespace Nz::ShaderLang
 			auto& extVar = externalStatement->externalVars.emplace_back();
 
 			if (token.type == TokenType::OpenAttribute)
-				extVar.attributes = ParseAttributes();
+			{
+				for (const auto& [attributeType, arg] : ParseAttributes())
+				{
+					switch (attributeType)
+					{
+						case ShaderAst::AttributeType::Binding:
+						{
+							if (extVar.bindingIndex)
+								throw AttributeError{ "attribute binding must be present once" };
+
+							if (!std::holds_alternative<long long>(arg))
+								throw AttributeError{ "attribute binding requires a string parameter" };
+
+							std::optional<unsigned int> bindingIndex = BoundCast<unsigned int>(std::get<long long>(arg));
+							if (!bindingIndex)
+								throw AttributeError{ "invalid binding index" };
+
+							extVar.bindingIndex = bindingIndex.value();
+							break;
+						}
+
+						default:
+							throw AttributeError{ "unhandled attribute for external variable" };
+					}
+				}
+			}
 
 			extVar.name = ParseIdentifierAsName();
 			Expect(Advance(), TokenType::Colon);
@@ -402,7 +446,35 @@ namespace Nz::ShaderLang
 
 		Expect(Advance(), TokenType::ClosingCurlyBracket);
 
-		return ShaderBuilder::DeclareFunction(std::move(attributes), std::move(functionName), std::move(parameters), std::move(functionBody), std::move(returnType));
+		std::optional<ShaderStageType> entryPoint;
+		for (const auto& [attributeType, arg] : attributes)
+		{
+			switch (attributeType)
+			{
+				case ShaderAst::AttributeType::Entry:
+				{
+					if (entryPoint)
+						throw AttributeError{ "attribute entry must be present once" };
+
+					if (!std::holds_alternative<std::string>(arg))
+						throw AttributeError{ "attribute entry requires a string parameter" };
+
+					const std::string& argStr = std::get<std::string>(arg);
+
+					auto it = s_entryPoints.find(argStr);
+					if (it == s_entryPoints.end())
+						throw AttributeError{ ("invalid parameter " + argStr + " for entry attribute").c_str() };
+
+					entryPoint = it->second;
+					break;
+				}
+
+				default:
+					throw AttributeError{ "unhandled attribute for function" };
+			}
+		}
+
+		return ShaderBuilder::DeclareFunction(entryPoint, std::move(functionName), std::move(parameters), std::move(functionBody), std::move(returnType));
 	}
 
 	ShaderAst::DeclareFunctionStatement::Parameter Parser::ParseFunctionParameter()
@@ -450,7 +522,41 @@ namespace Nz::ShaderLang
 			auto& structField = description.members.emplace_back();
 
 			if (token.type == TokenType::OpenAttribute)
-				structField.attributes = ParseAttributes();
+			{
+				for (const auto& [attributeType, attributeParam] : ParseAttributes())
+				{
+					switch (attributeType)
+					{
+						case ShaderAst::AttributeType::Builtin:
+						{
+							if (structField.builtin)
+								throw AttributeError{ "attribute builtin must be present once" };
+
+							auto it = s_builtinMapping.find(std::get<std::string>(attributeParam));
+							if (it == s_builtinMapping.end())
+								throw AttributeError{ "unknown builtin" };
+
+							structField.builtin = it->second;
+							break;
+						}
+
+						case ShaderAst::AttributeType::Location:
+						{
+							if (structField.locationIndex)
+								throw AttributeError{ "attribute location must be present once" };
+
+							structField.locationIndex = BoundCast<unsigned int>(std::get<long long>(attributeParam));
+							if (!structField.locationIndex)
+								throw AttributeError{ "invalid location index" };
+
+							break;
+						}
+					}
+				}
+
+				if (structField.builtin && structField.locationIndex)
+					throw AttributeError{ "A struct field cannot have both builtin and location attributes" };
+			}
 
 			structField.name = ParseIdentifierAsName();
 
@@ -461,7 +567,7 @@ namespace Nz::ShaderLang
 
 		Expect(Advance(), TokenType::ClosingCurlyBracket);
 
-		return ShaderBuilder::DeclareStruct(std::move(attributes), std::move(description));
+		return ShaderBuilder::DeclareStruct(std::move(description));
 	}
 
 	ShaderAst::StatementPtr Parser::ParseReturnStatement()

src/Nazara/Shader/SpirvWriter.cpp

@@ -27,12 +27,6 @@ namespace Nz
 {
 	namespace
 	{
-		//FIXME: Have this only once
-		std::unordered_map<std::string, ShaderStageType> s_entryPoints = {
-			{ "frag", ShaderStageType::Fragment },
-			{ "vert", ShaderStageType::Vertex },
-		};
-
 		struct Builtin
 		{
 			const char* debugName;
@@ -40,8 +34,8 @@ namespace Nz
 			SpirvBuiltIn decoration;
 		};
 
-		std::unordered_map<std::string, Builtin> s_builtinMapping = {
+		std::unordered_map<ShaderAst::BuiltinEntry, Builtin> s_builtinMapping = {
-			{ "position", { "VertexPosition", ShaderStageType::Vertex, SpirvBuiltIn::Position } }
+			{ ShaderAst::BuiltinEntry::VertexPosition, { "VertexPosition", ShaderStageType::Vertex, SpirvBuiltIn::Position } }
 		};
 
 		class PreVisitor : public ShaderAst::AstScopedVisitor
@@ -129,32 +123,13 @@ namespace Nz
 
 						UniformVar& uniformVar = extVars[varIndex++];
 						uniformVar.pointerId = m_constantCache.Register(variable);
-
+						uniformVar.bindingIndex = extVar.bindingIndex;
-						for (const auto& [attributeType, attributeParam] : extVar.attributes)
-						{
-							if (attributeType == ShaderAst::AttributeType::Binding)
-							{
-								uniformVar.bindingIndex = std::get<long long>(attributeParam);
-								break;
-							}
-						}
 					}
 				}
 
 				void Visit(ShaderAst::DeclareFunctionStatement& node) override
 				{
-					std::optional<ShaderStageType> entryPointType;
+					std::optional<ShaderStageType> entryPointType = node.entryStage;
-					for (auto& attribute : node.attributes)
-					{
-						if (attribute.type == ShaderAst::AttributeType::Entry)
-						{
-							auto it = s_entryPoints.find(std::get<std::string>(attribute.args));
-							assert(it != s_entryPoints.end());
-
-							entryPointType = it->second;
-							break;
-						}
-					}
 
 					assert(node.funcIndex);
 					std::size_t funcIndex = *node.funcIndex;
@@ -325,29 +300,12 @@ namespace Nz
 
 				UInt32 HandleEntryInOutType(ShaderStageType entryPointType, std::size_t funcIndex, const ShaderAst::StructDescription::StructMember& member, SpirvStorageClass storageClass)
 				{
-					std::optional<std::reference_wrapper<Builtin>> builtinOpt;
+					if (member.builtin)
-					std::optional<long long> attributeLocation;
-					for (const auto& [attributeType, attributeParam] : member.attributes)
 					{
-						if (attributeType == ShaderAst::AttributeType::Builtin)
+						auto it = s_builtinMapping.find(*member.builtin);
-						{
+						assert(it != s_builtinMapping.end());
-							auto it = s_builtinMapping.find(std::get<std::string>(attributeParam));
-							if (it != s_builtinMapping.end())
-							{
-								builtinOpt = it->second;
-								break;
-							}
-						}
-						else if (attributeType == ShaderAst::AttributeType::Location)
-						{
-							attributeLocation = std::get<long long>(attributeParam);
-							break;
-						}
-					}
 
-					if (builtinOpt)
+						Builtin& builtin = it->second;
-					{
-						Builtin& builtin = *builtinOpt;
 						if ((builtin.compatibleStages & entryPointType) == 0)
 							return 0;
 
@@ -364,7 +322,7 @@ namespace Nz
 
 						return varId;
 					}
-					else if (attributeLocation)
+					else if (member.locationIndex)
 					{
 						SpirvConstantCache::Variable variable;
 						variable.debugName = member.name;
@@ -373,7 +331,7 @@ namespace Nz
 						variable.type = m_constantCache.BuildPointerType(member.type, storageClass);
 
 						UInt32 varId = m_constantCache.Register(variable);
-						locationDecorations[varId] = *attributeLocation;
+						locationDecorations[varId] = *member.locationIndex;
 
 						return varId;
 					}